1982 L-82 claret red, claret red interior. Excellent car! Base/Clear paint NEW! Have painted hood 5 times, stripped it down to the fiberglass each time, ground out the fiberglass each time and still some bubbles come up toward the center/rear of hood but only after a while. Heat perhaps? Anyone else have this problem, or anyone know solution? Painted the rest of the car the same way with the same paint, no problems anywhere else.

If this makes you feel any better, you're not alone. Saw a C3 this last weekend with the same prob., but the bubbles were in the center and left.
Do the bubbles come up in the same places? 'Cause I'm thinking oil seepage from the underside. Heat is a likely guess, but why not on all Vettes? My C3 doesn't do it.
I'm really shootin' in the dark, so this is my best guess. Most times this is from prep. but it sounds like you're doing every thing right.

Have had my 68 since new, 95000 miles on it . had original British racing green on it which, after 20 years had some very small bubbles rise uo toward front of hood. After repaint (once) had bubbles again toward same areas. Original hood had no insullation. Painter said it was due to expanding fiberglass. Whatever!! I Live in Ca., temps may make a difference.
sounds like you have yo live with it. SORT OF LIKE HAVING PIMPLES AT AN EARLY AGE.

1982 L-82 claret red, claret red interior. Excellent car! Base/Clear paint NEW! Have painted hood 5 times, stripped it down to the fiberglass each time, ground out the fiberglass each time and still some bubbles come up toward the center/rear of hood but only after a while. Heat perhaps? Anyone else have this problem, or anyone know solution? Painted the rest of the car the same way with the same paint, no problems anywhere else.

hello.... what kind of primer is on the car.........when i first started painting glass cars i ran into this problem it was my primer ... i now use polyester resin primer never had this problem again...the glass does shrink and exspand and if the primer cant shrink on the glass you get bubbles...also if you any contamanation you will get bubbles to .... if the paint is really new you can poke with a needle ..i would heat the needle up then poke bubble to let the air out,,

I don't want to sound like a pro, but this ain't my first rodeo as far as painting fiberglass or anything else. I would agree with you about the poly resin primer but as I stated, absolutely no where else on the car has a blemish or bubble and it was all painted the same way/same time. The bubbles are really large blisters and they seem to come up at the same place every time. The real funny thing is, I painted the car in November of last year, and everything was just fine until we started driving the car alot and the weather heated up around May/June time frame, that is why I am thinking heat is the problem. As far as primer........I used 2 part Urethane primer, and again no problems anywhere else.

I am by no means a body man, done some painting though. (although not on glass)
Just curious, did you do the underside of the hood too?
Would a sealer on the underside help? I have heard that glass can get small fractures and seep when subjected to a lot of movement. Ex: The glass flexing when closing the hood, if drop closed as opposed to set closed.
A friend who collects Vettes told me to always release the lock, set the hood with your hand in the middle of the hood where it meets the windshield, and set the hood down. Then go to each side and firmly but gently press the corners to latch.
How about insulation, is it there?
I'm tryin' to learn too, just in case I end up with this prob down the line!